A tubular shaft which accommodates a tubular-type pump has a section situated above the pump that is a pressure line for the tubular-type pump. Accordingly, this section requires a pressure-tight seal about the openings through which the pump is lowered into the tubular shaft, and through which the lines leading to the electric motor of the tubular-type pump penetrate from and exit the tubular shaft. The lines and a carrying cable or carrying chain which may be permanently attached to the pump are exposed to the pressurized flow of the tubular-type pump. For this reason, they must be fastened as tightly as possible to forestall hindrances to the operation or damage due to motion in the pressurized fluid flow. When the tubular-type pump is lowered, care must be taken first to ensure that the pump is solidly seated on a support in the tubular shaft. The carrying cable or chain and the lines consequently can be tightened only after the pump has been lowered. On the other hand, when the tubular-type pump is pulled up, the carrying cable or chain and the lines must be relieved of tension and must be prepared for the subsequent processing.
The above circumstances necessitate a special design of the openings for passing the pump and the lines as well as a special design of the fastening point for the traction cable or chain. Here one must take into account that under certain circumstances, the motors used are sometimes very powerful and consequently lines with a large cross section are used, which can make it quite difficult to handle the lowering and lifting of the tubular-type pumps. The line conduits consequently are especially important.
It is indeed possible to lead the lines through the tubular shaft; however, because of the required bending radii of these lines, the tubular-type pump then cannot be pulled up without previously clamping and threading out the lines. This is quite complicated because the lines are so thick.
DE-GM 84 11 983 discloses a tubular shaft for accommodating submersible motor-driven pumps disposed therein. A two-part lid is used, such that only one part has penetrations for the lines. The two lid-segments can be of different size and are sealed with respect to one another and with respect to the tubular shaft. They can be detached from the tubular shaft independently of one another. In this way it is possible first to lower the pump into the tubular shaft and for bringing the lines into their operational state through the remaining opening. However, this solution is quite complicated. Furthermore, it requires skill and practice on the part of the personnel for the initial assembly and for the periodic maintenance work.